Chemical spray gun



y 9, 1956 E. J. FISHER 2,747,934

CHEMICAL SPRAY GUN Filed Oct. 5, 1951 IN VEN TOR.

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United States PatentOfiice 2,747,934 Patented May 29, 1956 1 2,747,934 CHEMICAL SPRAY GUN Emery J. Fisher, Chicago, ill. I Application October 5, 1951,- Serial No. 249,832

2 Claims. (Cl. 299-86) My present invention relates, generally, to a new and useful device for injecting a flow stream of one material into intimate admixture with a flow stream of another material. More specifically, my invention relates to innovations and new and useful improvements in spray guns of the type disclosed in Patent No. 2,433,463 to A. J. Lampe and my copending application Serial No. 137,873 filed January 10, 1950, now Patent No. 2,578,412 for spraying comminuted, granular, cellular or fibt'ou'sma terials and simultaneously spraying a liquid onto a blast of such a material as it is discharged from the gun.

The device of the present invention may be put to many uses, but for purposes of illustration and detailed disclosure the invention will be described in connection with spray guns of the type disclosed in the above mentioned patent and copending application which are used for spraying particulate'insulation materials onto walls, ceilings and other surfaces. In order for such a particulate material, which may be either for heat or sound insula tion, or both, to adhere to a wall or ceiling surface and form a continuous bonded-on coating or blanket, i t is necessary to at least partially coat the individual particles or fibers with a suitable binder or adhesive. This general method or technique of applyin and building up i'nats or 2 following detailed description thereof taken in connection with the accompanying drawings, wherein:

Fig. 1 is a top plan view of a spray gun which incorpo'rates one embodiment of the present invention;

Fig. 2 is a fragmentary sectional view on enlarged scale taken on line 2-2 of Fig. 1; and

Fig. 3 is a cross-sectional view taken on line 33 of Fig. 2.

The spray gun shown in Fig. 1 corresponds to the spray guns shown in Fig. 1 of Patent No. 2,433,463 and Fig. 1 of my copending' application Serial No. 137,873, and in addition it incorporates an embodiment of the present invention as part of the central conduit or pipe 1-1. A spray head 12 having circumferentially arranged adhesive discharge nozzles 13 -13 fits over the discharge end of the central pipe 11. The spray head 12 may have a construction corresponding either to that of the spray head coatings of sound and thermal insulation on surfaces is l disclosed in Patents Nos. 1,718,507, 1,888,841, 2,179,679 to Wenzel et al., No. 1,837,422 to Fix and NO'. 1,978,125 to Bennett. The spray guns disclosed in Lampe Patent No. 2,433,463 and my copending application Serial No. 137,873 comprise a central pipe or conduit of relatively large diameter over the discharge end of which is fitted a spray head carrying nozzles for spraying liquid adhesive onto the particles of insulation as they are blown from the discharge end of the central pipe. While these spray guns are practical and have given Very good service for the intended purpose, they do involve certain objections and disadvantages. For example, when an insulation material such as asbestos fiber or mineral wool is being sprayed, the operation is dusty and the spray gun operators are required as a safety measure to wear dust respirators. Furthermore, the dust makes it diflicult for the operator to observe closely what he is doing, and the work is difficult if the operator has to wear glasses or goggles. Furthermore, the dusty condition is objectionable where the work is being done in an occupied building, such as in a home or' restaurant, in which case it is necessary to isolate the room where the spraying is being done in order to prevent the dust from spreading to adjacent rooms and areas.

One of the important objects of this invention is the provision or a device for injecting a second material into intimate admixture and contact with a central flow stream of a first material. Specifically, an object of the invention is a device for injecting a second materi l, such as steam, water, or some other dusepievenring" liquid intothe central flow strea'tn passing flirongn one of the central pipes of a spray gun or the type disclosed in the above mentioned Patent No. 2,433,463 and my copending application Serial No. 137,873, In addition to steam and water, other-types of materials may be injected as will be pointed v out below.

Certain other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.

For a more complete understanding? of the nature and scope of the invention, reference may be had to the 1 disclosed in Patent No. 2,433,463 or that of the spray head shown and disclosed in my copending application Serial No. 137,873. Reference is hereby made to Patent No. 2,433,463 and my copending application for a detailed description of the construction of the spray head 12'. Air under pressure is supplied to the spray head 12 through the air line 13 provided with a valve 14 and adhesive is supplied under pressure through the adhesive line 15 provided with a valve 16. In operation, the air atomizes the adhesive and discharges it through the nozzles 19, the latter being canted or pitched so that the streams of adhesive converge properly on the particles of insulation discharged from the end of the central pipe or conduit 11. inthis manner the particles of insulation are coated with adhesive so as to adhere to each other and to a wall surface onto which the spray is directed.

The central pipe 11 passes through a central opening provided therefor in the spray head 12. Rearward'ly of the spray head 12 a ring fixture 17 fits over the central pipe 11 and is provided with diametrically extending ears 18-1 8 having apertures therein for the air and adhesive lines 13 and 15. The fixture 17 is provided with a plurality of set screws 20-20 which serve to lock the fixture on the central pipe 11 and to secure the lines 13 and 15 in place.

The embodiment of the present invention which is used to inject steam or other material into the flow stream of material passing through the central pipe 11 is positioned between the fixture 17 and the spray head 12. This embodiment is designated generally at 21 in Fig. 1.

As shown in Fig. 2, the central pipe 11 has two conduit sections which are designated at 11a and 11b. These conduit sections are coaxially aligned and the adjacent ends are spaced apart su'fiici'ently to provide a circumferentialor band-shaped inlet opening which is designated at 22. Improved operation of the mixing device is obtained by having the juxtaposed ends chamfered or beveled at the same angle and in such a way that one of the beveled edges mates with the other. This construction imparts a pitch to the band-shaped opening 22 so that material discharged therethrough into the central pipe 11 tends to form a conical ly-shaped injection spray. From the standpoint of improved operation and ease of manufacture, I prefer to have the central pipe 11 made in two sections as described above. However, the band-shaped opening 22 is in efiect' a continuous series of openings and instead of having the opening completely continuous, there may be spaced interconnections between the sections 11a and 11b. The disclosure and the claims are intended to comprehend this obvious modification.

The central pipe 11 is jacketed on opposite sides of the band-shaped opening 22 by means of a cylindrical sleeve member 23 having integrally formed end walls 3 or flanges and 7.5 which lit with rather close tolerance over the conduit sections 11a and 11b, respectively. The sleeve 23 forms an annular chamber 26 around the central pipe 11, this chamber extending on opposite sides of the band-shaped opening 22.

In order to establish a rigid and fiuid type connection between the opposite ends of the sleeve 23 and the respective conduit sections 11a and 11b, gaskets 27-27 of a suitable compressible material such as rubber or neoprene are provided on opposite ends of the sleeve 23. Ring-shaped clamping members 28 and 3t fit over the sections 11a and 11b, respectively, on opposite ends of the sleeve member 23. A plurality (e. g. four) of bolts 31-31 equally spaced around the ring 28 serve to draw up this ring to the adjacent end 24 of the sleeve 23 so as to compress one or" the gaskets 27 therebetween and cause it to form a fluid-tight seal around the pipe section 110. In a similar manner the ring 30 is provided with bolts 3232 for putting the other gasket 27 under compression. In order to provide an inlet opening for introducing a second material into the chamber 26, the ring member 28 and the end wall 24 are provided with registering inlet openings 33 and 34, the opening 33 being tapped and provided with an inlet connection 35 over which is fitted one end of a steam hose 36. The interposed gasket 27 is also provided with a registering opening, as shown.

In order to more uniformly discharge a second material from the annular chamber 26 into the central pipe 11 through the band-shaped opening or split 22 into the pipe 11, the sleeve 23 is provided with an inner baffle 37 which is ring-shaped and closes off the annular space between the exterior of the section 11a and the interior of the sleeve 23, as shown. The ring-shaped baffle 37 is provided with a plurality of openings or holes 38-38 and the bathe is so inclined or canted that these holes 38 are coaxially aligned with the pitch of the band-shaped opening 22. This alignment facilitates the operation of the mixing device in that the material discharged through the openings 28 can flow in a direct stream into the conduit 11 and turbulence is minimized. The same result may be obtained with an alternate construction wherein the baffle wall 37 would be normal to the sleeve 23 and the conduit section 11a but the perforations therein would be drilled at an angle which would coaxially align these holes with the pitch of the band-shaped opening 22. The ring-shaped baffle 37 may be integrally formed on either the sleeve 23 or on the conduit section 11a, preterably the former, or it may be a separate element which is suitably secured to either or both of these parts.

The spray gun shown in the drawings and described above has been successfully operated in several different ways in applying sprayed-on thermal and acoustical insulation. In one method of operation the spray gun was operated in the usual manner in that dry particulate insulation materials, e. g. asbestos or mineral wool fibers, were blown through the central pipe 11 and a suitable adhesive was sprayed onto these articles of insulation as they discharge from the end of the central pipe 11. At the same time steam pressure was applied through the line 36 and the steam passed through the chamber 26 around the conduit section 11a, through the apertures 38 in the bathe 37, through the band-shaped opening 22 and thence into the main stream in the pipe 11, the course of How being indicated by the arrows in Fig. 2. Sufficient steam was introduced in this manner so as to moisten the particles of insulation just sufficiently to prevent dusting. The introduction of steam in this manner completely prevented dusting when the spray gun was operated. Where the combination of insulation material and adhesive is such that moisture on the insulation particles would be objectionable as the anti-dusting material, then a compatible material, such as a hydrocarbon solvent, may be introduced through the mixing device in place of the steam.

' or thermal insulation or both are applied, it is desired that the insulating material be fireproofed if the insulating fibers are of a combustible nature, such as is shredded paper or cellulose. The spray gun shown in the drawings has been successfully used in handling this type of insulation material by introducing into the main flow stream in the pipe 11 through the mixing device of the present invention a solution of a fireproofing chemical which serves to prevent dusting and at the same time coat the particles with a fireproofing material.

In addition to the foregoing uses, it will be apparent to those skilled in the art that the mixing device of the present invention may be put to many other uses. Broadly, the mixing device may be employed to intimately admix any desired second component or material into the main stream flowing through the conduit or pipe 11. In addition to dust-preventing and fireproofing materials, other materials that may be introduced include coloring materials, odor-imparting materials, preservatives, insecticides, etc. It is also possible to remove the spray head 12 and to utilize the mixing device of the present invention to introduce an adhesive onto the particles of insulation material passing through the central pipe 11.

Certain other uses of the invention will be apparent and occur to those skilled in the art. Since certain modifications and changes in design may be made in the embodiment of the invention shown in the drawings and described above, and since other embodiments of the invention may be made without departing from the spirit and scope of the invention, the particular embodiment described above and shown in the drawings is intended to be taken as illustrative and not to be interpreted in a limiting sense.

What is claimed as new is:

l. A device for injecting a second material into intimate admixture with a central flow stream of a first material, comprising, a central conduit formed by two conduit sections disposed in coaxial end-to-end relationship with one another with a sufficient space between the adjacent ends to form a band-shaped inlet opening in the wall of said conduit, the adjacent ends of said conduit Sections being matingly beveled so as to give a pitch to said band-shaped opening, a housing fitting over said conduit in fluid-tight relationship so as to form an outer annular chamber therearound with the opposite ends of said housing lying on opposite sides of said band-shaped opening, and a ringshaped bafile within said chamber adjacent the end of that conduit section which has the male bevel on its end, said batfie having a plurality of openings circumferentially arranged therein, said openings having approximately the same pitch as the pitch of said band-shaped opening and being in flow alignment therewith, and said housing having an inlet opening therein located to the side of said baffie opposite the band-shaped opening whereby when a second fluid material is introduced into said chamber it is distributed through said baflie openings and then through said band-shaped opening into said central conduit.

2. The combination with the device called for in claim 1 of a spray head mounted over the discharge end of that conduit section which is downstream from said battle for spraying material onto material issuing from said discharge end, said spray head having a plurality of spray nozzles for spraying a liquid material onto material as it is discharged from saiddischarge end.

References Cited in the .file of this patent UNITED STATES PATENTS 1,458,523 Coutant June 12, 1923 2,433,463 Lampe -Q. Dec. 30, 1947 2,563,002 Bissell Aug. :1, 1951 2,578,412 Fisher Dec. 11, 1951 

